The goal of this PPG is to advance our understanding ofthe complex regulation and interplay of a set of genes residing in two different regions of chr 13 but which together are responsible, in large measure, for salt-induced hypertension, renal injury, and vascularity/angiogenesis of the microcirculation in the saltsensitive (SS) rat. The studies are collectively designed to explore how genetic polymorphisms are translated into integrated cellular, tissue, organ and whole animal function. Project 1 hypothesizes that sequence variants of one or more ofthe genes within a congenic region of chr 13 alter molecular regulatory networks affecting function of the medullary thick ascending limb (mTAL) of SS rats and contribute to the development of salt-sensitive hypertension and renal injury. This will tested by: 1) generating finished-level genomic sequence with complete annotation of this congenic region;2) by constructing a molecular and physiological regulatory network of the mTAL epithelial cell and identifying pathways and genes that may contribute to hypertension and renal injury;and 3) by studying the impact of removing or overexpressing an important gene in the transcriptome/proteome/metabolome associated network. Project 2 will examine a novel hypothesis that non-protein-coding genes may play important roles in hypertension and related tissue injury. We hypothesize that miR-214 contributes to the development of salt-sensitive hypertension and renal injury and examine: 1) the functional contribution of the microRNA within the kidney;2) examine downstream mechanisms mediating its effects, examine upstream trans and cis mechanisms;and 3) carry out a pilot study of miR-214 in human salt-sensitive hypertension and renal injury. Project 3 hypothesizes that a mutation(s) in the SS rat is responsible forthe impaired angiogenesis in this model. We will: 1) identify sequence variants;2) demonstrate that these variants impact renin regulation in vitro;and 3) using a transgenic approach, demonstrate that the SS allele is capable of eliminating normal renin regulation and the angiogenic phenotype in vivo. The collaborative research of this PPG will be supported by Administrative Core A, Genomic and Transgenic Core B, and the Research Services Core C.